Polymeric defoamer additive

ABSTRACT

The present invention relates to a cost-effective and environmentally friendly polymeric defoamer formulation for use in various industrial applications that does not contain oil, EBS or free silicone.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the use of polymers containing alkylacrylates, hydroxyalkyl acrylates, and/or acrylic acid for defoaming inpulp and paper mill operations, particularly for use toward pulp millblack liquor as well as in the petroleum industry, water treatment,paints and coatings, food and beverage processing, the mining industry,textiles, agriculture, and the like.

BACKGROUND OF THE INVENTION

Defoamers are compositions used in the pulp and paper mill industry forthe control of foam in various processes. In addition to the pulp andpaper industry, defoamers are also useful in the petroleum industry,water treatment, paints and coatings, food and beverage processing, themining industry, textiles, agriculture, and the like.

Foam control is a common industrial problem. As such, defoamers arebeing developed to alleviate this problem. Common defoamer compositionsare generally composed of a carrier fluid, a defoaming agent andmiscellaneous additives. Foaming problems often have been effectivelydealt with by using various petroleum oil-based compositions containingan alkylene diamide and/or hydrophobic silica (silicone coated silica),as well as silicone emulsions and concentrates. Further, cost effectivecarrier fluids have often been the petroleum oils (mineral oils). Wateris also often part of defoamer formulations. Various defoamingcompositions have been documented in product literature and patents.See, e.g., U.S. Pat. Nos. 5,082,590; 5,096,617 and 5,071,591.

Oil-based amide defoamers contain a minimum of two ingredients: a waxwith a high melting point and an oil carrier (usually derived frompetroleum), in which the wax is dispersed. A commonly used wax class isthe diamides. A common diamide is ethylene bis-stearamide (EBS), butother diamides or mixtures of diamides can also be found in defoamerblends. EBS is a very hydrophobic molecule that can have depositionpotential if not formulated and used correctly. There have beeninstances where EBS has been found in unwanted deposits in pulp andpaper mills. Deposition can lead to discontinuing introduction ofdefoaming agents that are believed to contribute to the depositionevent.

The typical weight fraction of diamide is between about 2 and 10% of thecomposition whereas the weight fraction of the petroleum oil is oftenover 80%. The carrier oil varies in composition from one defoamer toanother but generally consists of a low viscosity mineral oil withparaffinic or cycloparaffinic hydrocarbons. In addition to the diamidesand petroleum oil, the blends may also contain other agents such ashydrophobic silica and silicone oil, various emulsifiers, andstabilizers, but these constituents generally comprise less than about10% of the formulation.

While these diamide-based compositions are effective defoamers, theyhave been suspected of contributing to deposition problems in variouslocations in the mills. (Dorris et al. “Analysis of Amide Defoamers inKraft Mill Pitch Deposits,” J. Pulp & Paper Science, 11:5, J149-J154,September 1985) There is some evidence that the petroleum oil in thistype of defoamer can lead to undesirable by-products in Kraft bleachplants (Allen. et al. manuscript distributed at the 8th InternationalSymposium on Chlorinated Dioxins and Related Compounds, Urnes, Sweden,Aug. 21-26, 1988) In addition, they can demonstrate limited performanceefficiency on paper machines because they are not able to completelydisperse in water thus they have potential to form deposits and/or oilspots in the paper produced.

Alternative petroleum oil-based defoamers have been prepared from a widevariety of chemicals. For example, U.S. Pat. Nos. 3,751,373 and3,935,121 disclose defoamers based upon a combination of a fatty acid oralcohol, a polyethylene glycol mono- or di-ester of a fatty acid, apetroleum sulfonic acid, and an organic liquid.

An example of a commercial aqueous-based defoamer is an aqueous emulsionof fatty alcohols. Although the aqueous defoamer does not containpetroleum oil phase, it does however, contain high melting waxes whichhave been associated at times with undesired effects in processing.These defoamers are generally not as effective as those containing EBSand their homologues, but also do not cause the spotting problem onpaper machines that are associated with formulations containing oil, EBSor silicone.

Silicone has commonly been implicated as a contributor to somedeposition issues in various processing steps. If not properlyformulated and applied, these materials can cause similar or the sameproblems as oil-containing defoamers. As a result, many pulp and papermills avoid using silicone containing products.

Therefore there is a need for a cost effective and environmentallyfriendly defoamer formulation which does not contain oil, EBS or freesilicone and performs as good as, if not better than pre-existingdefoamers.

SUMMARY OF THE INVENTION

The present invention relates to a cost-effective and environmentallyfriendly defoamer formulation which does not contain oil, EBS or freesilicone for use in various industrial applications. The defoamerformulation of the present invention comprises a mixture of polymercontaining acrylic acid, methacrylic acid, or a combination or either ina suitable diluent, an organic carrier, an additive, and/or asurfactant.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed towards a cost-effective andenvironmentally friendly polymeric defoamer formulation for use inseveral industrial applications including, but not limited to: i)controlling or destroying foam in various processes associated with pulpand paper processing, such as in the Kraft pulping process, sulfitepulping process, thermomechanical pulping (TMP) process, Chemical TMP(CTMP) process, groundwood pulping process, carbonate pulpingprocess,paper machine processes, screen rooms, bleach plants, and the like; ii)preventing inhomogenuity such as craters and rough appearances fromforming due to entrained air during the manufacturing of paints and/orcoatings for metal, wood, plastics, concrete, and the like; iii)preventing streaking during ink production caused by air bubbles; iv)efficiently controlling flow properties of cement by minimizing airentrainment in the cement slurry; v) increasing drilling efficiency inoil wells by minimizing the effects of unwanted air; vi) controllingfoam production during treatment of municipal and commercial wastewater; vii) reducing foam buildup associated with the production andstorage of ethanol fuel along with cleaning production vessels; viii)preventing and controlling foam buildup associated with the storage offertilizer in spray tanks in order to free vessel space; ix) preventingthe formation of foam buildup in fluids used during metalworking; x)preventing foam buildup and overflow during syntheses of ActivePharmaceutical Ingredients (API); and xi) controlling foam producedduring the washing process prior to plastics recycling.

The new defoamer formulation of the present invention unexpectedlyproduces increases in performance over traditional defoamer technology.Further, the addition of acrylic acid or methacrylic acid to the monomerpremix increased performance over monomer premix that did not haveacrylic acid or methacrylic acid. The performance was unexpectedlyhigher than traditional technology at equal dosages.

The essential constituents of the defoamer formulation comprise anacrylate or methacrylate polymer with or without acrylic acid ormethacrylic acid in a suitable diluent, organic carrier(s), an additive,and/or a surfactant.

The combination of different monomers in the polymer composition mayalso be used. The most robust performance is observed when the polymercontains acrylic acid as well as an alkyl acrylate and a hydroxyalkylacrylate. The addition of acrylic acid to the polymer chaindifferentiates the polymeric defoamer formulation of the presentinvention from other polymers used in the past to enhance defoamerperformance. The use of methacrylate derivatives are effective as wellagainst foam. A defoamer containing methacrylate derivatives outperformsformulations consisting of the acrylate analogues.

Monomers:

Examples of general monomers used singly or in combination in thepresent invention to form polymers which are soluble in organic solventsare acrylates, methacrylates, styrene, acrylonitrile, vinyl alkylethers, vinyl alkyl esters, hydroxyl alkyl acrylates and methacrylates,fumaric and maleic acid diesters, vinyl acetate, acrylic acid,methacrylic acid, and the like. The preferred general monomers used inthe present invention are acrylates and methacrylates.

The preferred monomers of the present invention are of the generalformula:

wherein R is hydrogen or methyl.

R′ is hydrogen or a linear or branched alkyl group containing from about1 to 18 carbon atoms and/or at least one hydroxy group anywhere on thealkyl chain. Suitable R′ groups are selected from, but not limited to,2-ethylhexyl, 1-, 2-hydroxyethyl, 1-, 2-, or 3-hydroxypropyl, 1-, 2-, or3-hydroxyisopropyl, or 1-, 2-, 3-, or 4-hydroxybutyl.

The most preferred acrylate monomers include 2-ethylhexyl acrylate(2EHA), 2-hydroxyethyl acrylate (2HEA), and/or acrylic acid.

The most preferred methacrylate monomers include 2-ethylhexylmethacrylate, 2-hydroxyethyl methacrylate, and/or methacrylic acid.

Polymers:

Acrylate polymers useful in the present invention are those polymersobtained by polymerization of one or any combination of an alkylacrylate monomer, a hydroxyalkyl acrylate monomer and/or acrylic acidmonomer. Methacrylate containing polymers that are also useful in thepresent invention are those polymers obtained by polymerization of analkyl methacrylate monomer, a hydroxyalkyl methacrylate monomer, and/ormethacrylic acid monomer, or combinations of acrylates andmethacrylates.

The polymers of the present invention may be prepared in any suitablemanner known by one of ordinary skill in the art Generally, they will beprepared with or without the addition of acrylic acid or methacrylicacid in an organic diluent in the presence of a free radical generatingcatalyst.

The amount of acrylic acid and/or methacrylic acid that may be used inthe monomer premix for the preparation of the polymers is selected from,but not limited to, up to about 25 mol % of the polymer, preferably fromabout 1 to 20 mol % of the polymer, and most preferably about 8 mol % inthe polymer.

Organic Diluents:

Examples of suitable organic diluents for use in the present inventionmay be selected from, but not limited to, diisodecyl phthalate,diisooctyl adipate, diisooctyl phthalate, bis-2-ethylhexyl adipate,dioctyl adipate, 2-ethyl-1-hexanol, isooctyl alcohol, dihexyl phthalate,and/or mixtures thereof. Preferred diluents are diisodecyl phthalate anddiisooctyl adipate, with the most preferred being diisooctyl adipate.

Catalysts:

Examples of free radical generating catalysts for use in the presentinvention may be selected from, but not limited to,2,2′-azobis(2-methylpropanenitrile),2,2′-azobis(2,4-dimethylpentanenitrile), or2,2′-azobis(2-methylbutanenitrile). The most preferred free radicalgenerating catalyst is 2,2′-azobis(2-methylpropanenitrile).Alternatively, redox catalyst systems such as bromate/sulfide orpersulfate/ferrous systems may be used. In addition, peroxides such asbenzoyl peroxide may be used to generate the free radicals. Alternativefree radical generating catalysts may be used as disclosed in U.S. Pat.No. 5,152,925, which is herein incorporated by reference in itsentirety.

Organic Carriers:

Examples of suitable organic carriers for use in the present inventionmay be selected from, but not limited to, the same organic diluents usedto make the polymers, polybutenes having a molecular weight of fromabout 300-1300 atomic mass units, dialkyl phthalates, fatty acid esters,polyethylene and polypropylene glycol and esters thereof, and the like,or mixtures thereof. The preferred organic carriers are polybuteneshaving a molecular weight of from about 300-1300 atomic mass units andpolypropylene glycol, and most preferably polypropylene glycol.

Surfactants:

Examples of suitable surfactants for use in the present invention may beselected from, but not limited to, polyethylene glycol, polypropyleneglycol, polypropylene triol, butoxy polypropylene polyethyleneglycol,alkoxylated dimethylpolysiloxane, alkyl modified siloxanes,fluorine modified siloxanes, mercapto modified siloxanes, hydroxymodified siloxanes, siloxane wax, ethylene oxide/propylene oxide blockcopolymer, the esters of polyethylene glycol, polypropylene glycol,polypropylene triol, butoxy polypropylene polyethylene glycol, ethyleneoxide/propylene oxide block copolymer, alkylpolyoxyethylene ethers,alkylpolyoxyethylenes, polyoxypropylene ethers, fatty acidpolyoxyethylene esters, fatty acid polyoxyethylene sorbitan esters,fatty acid polyoxypropylene sorbitol esters, polyoxyethylene castoroils, alkylpolyoxyethylene amines and amides, fatty acid sorbitanesters, fatty acid polyglycerin esters, fatty acid sucrose esters, andthe like. The preferred surfactants are siloxane-based andpolypropylene-polyethylene glycol, and most preferablypolyether-modified polysiloxanes and/or alkyl modified siloxanes.

Additives:

Examples of suitable additives for use in the present invention may beselected from, but not limited to, hydrophobic silica, waxes, fattyalcohols, fatty acid esters, fatty alcohol esters, or fatty acids, withthe most preferred being hydrophobic silica.

The introduction of surfactants and additives into the resultingdefoamer formulation of this invention improves initial and/or overallperformance of the defoamer formulations of the present invention.Moreover, it is understood that routine experimentation by one ofordinary skill in the art will determine which and how much specificsurfactants and other materials are to be used for a particularapplication.

Formulations:

The final defoamer formulation may contain a mixture of up to about 60%acrylate or methacrylate polymer with or without acrylic or methacrylicacid in a suitable diluent, about 20-80% organic carrier, up to about15% additive, and/or up to about 30% surfactants of varyingcompositions. If acrylic or methacrylic acid is used, the molepercentage of said acid may be up to about 25 mol %.

A preferred mixture of the final defoamer formulation may contain about15-35% acrylate or methacrylate polymer with or without acrylic ormethacrylic acid in a suitable diluent, about 30-70% organic carrier, upto about 10% additive, and about 5-25% surfactants. If acrylic ormethacrylic acid is used, a preferred ratio of said acid is about 5-15mol %.

Another preferred mixture of the final defoamer formulation may containabout 20-30% acrylate or methacrylate polymer with or without acrylic ormethacrylic acid in a suitable diluent, about 40-60% organic carrier,about 3-10% additive, and about 10-15% surfactants. If acrylic ormethacrylic acid is used, a preferred ratio of said acid is about 8 mol% of the polymer.

One of ordinary skill in the art will appreciate that the individualcomponents of the present invention may change in the formulationsdepending on the physical and chemical qualities needed for the defoamerin a given process and/or application to which the defoamer will beapplied. For example, the dispersibility of the defoamer in water can beadjusted as necessary to obtain the desired performance. An examplewould be a brown stock washer, paper machine, effluent, and paintdefoamer would all have different water dispersibility properties basedon their needs.

Depending on the physical and chemical qualities that are needed for agiven application or process, the typical dosage or feed rate of fromabout 2-50 parts per million (ppm) of defoamer will be suitable

Uses:

The formulation of the present invention will effectively prevent foamformation and/or destroy preexisting foam in a variety of industrialapplications. Further more, the defoamer formulation of the presentinvention may or may not be water dispersible.

The cost-effective and environmentally friendly polymeric defoamerformulation is particularly useful in pulp and paper processing. Thedefoamer formulation of the present invention can be applied in bothalkaline and acidic processes in pulp mills without the use of mineraloil, Ethylene bis-stearamide (EBS), or free silicone fluid. The defoamerefficiently controls or destroys foam in various processes, such as butnot limited to the Kraft pulping process, sulfite pulping process,thermomechanical pulping (TMP), chemical TMP (CTMP), groundwood pulping,carbonate pulping, paper machine processes, screen room, and bleachplant.

The formulation of the present invention is efficient as a defoamer inthe paint and coating industry. The formulation prevents, among otherthings, undesirable inhomogeneity such as craters and rough appearancesfrom forming due to entrained air during the manufacturing of paints orcoatings for metal, wood, plastics, concrete, and the like. In addition,the defoamer formulation also efficiently controls foam buildup in thepolymer emulsion associated with water-based PVC paints.

In the ink industry, the formulation of the present invention, amongother things, effectively removes and/or controls air bubbles formedduring ink production. This in turn prevents any streaking or crateringin the ink, thereby providing a uniform, high quality ink product.

The defoamer formulation is also useful in the cement industry in orderto, among other things, efficiently decrease foam production duringpreparation of cement slurries. As such, air entrainment in the cementslurry is minimized, thus leading to increased flow properties in thecement. The minimization of air entrainment in the cement slurry alsoresults in a more structurally sound cement lattice.

In the oil industry, the formulation of the present invention is alsouseful as a defoamer. For instance, when added to an oil well, thedefoamer effectively lowers the interfacial tension of the crude oil,thus allowing entrained gas to easily escape. This in turn, leads to anincrease in drilling efficiency. In addition, the defoamer alsoeffectively controls air entrainment in crude oil during the heatingprocess in distillation columns.

The foam buildup and air entrainment commonly associated with thetreatment of waste water in municipal and commercial settings, such asclarifiers, flumes, outfalls, effluent ponds, and the like, areeffectively controlled by the formulation of the present invention.Further, the formulation also effectively controls foam and airentrainment in both cold and hot applications.

In the fuel ethanol processing industry, the formulation of the presentinvention is effective in reducing foam buildup associated with theproduction and storage of ethanol fuel along with facilitating effectiveCIP (Cleaning-In-Place) of, among others, evaporators, bottle-washingapplications, or anywhere foam may need to be eliminated.

Additionally, for non-fuel ethanol fermentation processes, theformulation is also effective in controlling foam produced by enzymeswithout compromising either enzyme performance or ethanol quality.

In the fertilizer industry, the formulation efficiently prevents and/orcontrols foam build-up in spray tanks as a result of, for example,addition of phosphate rock to nitric acid. Addition of the formulationdirectly to the spray tanks prevents the formation of foam withoutaffecting the performance of the fertilizer. This in turn, frees reactorcapacity, which would otherwise be occupied by foam.

The defoamer formulation of the present invention is also useful in themetalworking industry. The formulation effectively prevents theformation of foam in various metalworking fluids, such as soluble oil,semi-synthetic, synthetic, micro-emulsion fluids, and the like duringmetal production.

In the food and beverage processing industry, the formulation of thepresent invention efficiently prevents and/or destroys foam productionin vessels used for washing, cutting, heating, and the like. As aresult, overflow of foam out of the vessels is prevented and more vesselspace is made available.

The formulation of the present invention is also useful as a defoamer inthe medical and pharmaceutical industries without compromising theeffectiveness of the Active Pharmaceutical Ingredient (API). Theformulation effectively prevents and/or destroys foam production inreaction vessels during large-scale syntheses of API's, which alsoprevents the foam from overflowing out of the reaction vessels.

In the plastics recycling industry, prior to recycling, the plasticsmust be washed with detergents. The conditions are rather harsh withhigh temperatures and highly basic pH's. As a result, severe foaming isproblematic. The defoamer formulation of the present inventioneffectively controls the foaming associated with the detergents andharsh conditions associated with plastics recycling.

The defoamer formulation of the present invention is in no way limitedonly to the uses discussed above. As such, the defoamer formulation ofthe present invention can also be used in any industry that may requirethe control or destruction of foam.

ABBREVIATIONS AND DEFINITIONS

“Foam” is defined herein to mean a dispersion of a gas (usually air) ina liquid or solid.

“Defoamer” is defined herein to mean a compound or composition used toinhibit the formation of foam or destroy existing foam.

“Water dispersible” is defined herein to mean a liquid, semi-solid, orsolid which is not soluble in aqueous media, but rather can be uniformlydistributed in an aqueous media.

“Water insoluble” is defined herein to mean a liquid, semi-solid, orsolid which is not capable of being completely dissolved or uniformlydistributed in an aqueous media.

“Aqueous media” is defined herein to mean media in which water is themain constituent. Aqueous media may comprise water that is completelyclear, a colloidal suspension, pulp slurry, and the like.

“Free silicone” is defined herein to mean silicone that is not bound toanother non-silicone constituent.

“Dose” is defined herein to mean the amount of defoamer formulationneeded to be added to a particular application or process to achieve adesired positive outcome.

“CIP” as used herein refers to Cleaning-In-Place and is defined hereinto mean spray cleaning a vessel with a minimum amount of hand detailing.

“2EHA” as used herein refers to 2-ethylhexyl acrylate.

“2HEA” as used herein refers to 2-hydroxyethyl acrylate.

“DIOA” as used herein refers to diisooctyl adipate.

“DIDP” as used herein refers to diisodecyl phthalate.

“PVC” as used herein refers to polyvinyl chloride.

“Room temperature” as used herein refers generally to temperatures inthe range of 20 to 30° C., with an average temperature being 25° C.

EXAMPLES Evaluation of Samples

The Foam and Entrained Air Tester (FEAT) is a testing apparatus used todetermine the efficacy of defoamers in a laboratory setting. Theapparatus measures the change in the density of the liquor/filtrate asthe defoamer is introduced. Traditional defoamer foam cell tests onlymeasure the effects a defoamer has on the surface foam. The measure ofthe change in density of a filtrate is a direct measurement of thechange in entrained air. In pulp and paper mills, presence of entrainedair can impede mat formation and drainage.

Testing of the different samples utilizes a recirculatory foam cellattached to a pump. The hose leading from the pump is connected to adensity meter, which is then connected back to the top of the foam cell.Black liquor from the first stage washer from a southeast Georgia Kraftprocess mill is used in all of the testing. The liquor is heated to 82°C. The heated black liquor is added to the test unit and pumped throughthe unit to fill the lines. The level of the liquor is then lowered tothe 18 cm mark on the tube before the test is started. Once the pump isturned on, the defoamer is added when the density dropped, due to airentrainment, to a specified density measurement, usually between 0.8 and1.0 g/cc. The tests are run for a total of 180 seconds. A line graph isthen generated to show the change in density of the liquor of the timeperiod. The area under the curve for each test is then calculated. Thereare two different areas calculated: the area under the curve during thefirst 30 seconds is calculated to provide a measure of the initialdeaeration of the sample, and the area under the curve for the totaltest time is calculated to provide a measure of the overall performanceof each sample. Those samples having the highest area under the curvemeasurements are those samples that performed the best. All tests wererun in duplicate and the averages of the two runs are reported. Resultsare reported both as area under the curve and as a percent differencewhen compared to the standard. Unless otherwise noted, the standards arethe example products from the patent. The range of experimental errorfor this test method is +/−10%. Testing of other filtrates (effluent,paper machine, starch, etc.) was completed using the above method aswell. Table 1 below is merely an illustration of how data is presentedin the following examples.

TABLE 1 Example of Results: Product 1 Product 2 Product 3 Product 4 3000μL 3000 μL 200 μL 1000 μL 1st 30 Seconds 12.3 12.3 11.0 10.1 Area TotalRuntime 72.3 74.4 85.4 61.9 Area Percent Difference from 2.9% 18.1%−14.3% Standard

Table 1 above shows the product name and the dosage used for that test(Product 1, dosed at 3000 μL). The number below the name and dosage isthe area under the curve during the first 30 seconds of the test(12.31930). The second number is the area under the curve for the entiretest time (72.28433). The bottom numbers are the % differences in totalarea between the standard/control's total area under the curve and theexperimental samples' total area under the curve. In the case above,Product 3, dosed at 200 μL, yielded an 18.1% increase in performanceover Product 1. Product 4, dosed at 1000 μL, yielded a 14.3% decrease inperformance when compared to Product 1. In the above example, Product 3would be the best performing product—not only did the product provide an18% increase in performance, the product accomplished the increasedespite having a dosage that was 1/15^(th) that of the standard, Product1.

All parts and percents are by weight unless otherwise specified.Additionally, all trademarks are defined throughout the specification.

Example 1 Preparation of Acrylate Polymer in DIOA

A polymer containing 10-30% hydroxyl alkyl acrylate and 70-90% alkylacrylate by weight percent was prepared as follows: 250 g of diisooctyladipate (DIOA) was placed into a reaction flask. A vacuum was appliedfor 20 minutes to remove dissolved air. DIOA was sparged with nitrogenwhile being heated to 79-82° C. with mixing. Once at temperature andwith the nitrogen sparge and constant mixing, a free radical generatingcompound was added and allowed to dissolve over a 5 minute period.Meanwhile, the acrylate monomers were pre-mixed in a beaker. The monomermixture was added to the DIOA diluent through an addition funnel at arate of approximately 1.5 g/minute, making sure to maintain atemperature of approximately 79-82° C. After the monomer blend addition,48 g of DIOA were used to rinse the monomer blend container and additionfunnel, and the DIOA rinse was added to the reaction flask. Another 0.5g of free radical generating compound was added, and the mixture washeld at 79-82° C. with mixing and nitrogen for 2 hours. The mixture wasthen air cooled to room temperature.

The resulting polymer was clear and colorless, having a viscosity of1100 cps as measured by a Brookfield viscometer, spindle 3, speed 50 at25° C.

Example 2 Comparison to Example II of U.S. Pat. No. 5,152,925 ('925)

Experimental products were made following the formulations given inExample II of the '925 patent. Analogs of the examples were also madeusing the polymer from Example 1 above. Below are the formulations,along with their corresponding numerical designations, i.e., 265-57-1.

TABLE 2 Example Products from the ′925 Patent 265-57-1* (standard)265-55-1 265-57-3 Polybutene 70 50 DIDP 70 20 Acrylate Polymer in 30 3030 DIDP *Example from the ′925 patent

TABLE 3 Analogs of the ′925 Patent Examples with Acrylate polymer inDIOA 265-57-2 265-55-2 265-57-4 Polybutene 70 50 DIDP 70 20 AcrylatePolymer in 30 30 30 DIOA

TABLE 4 Best Previous Performing Defoamer 265-54-2 Polypropylene Glycol58.5 Hydrophobic Silica 3 Acrylate Polymer in DIOA 23.5Polyether-Modified 10 Polysiloxane Silicone Surfactant Alkyl ModifiedSiloxane 5 Silicone Wax

TABLE 5 Polybutene Containing Samples* 265-55-1 265-55-2 265-54-2 3000μL 3000 μL 200 μL 1st 30 Seconds 6.5 8.4 11.2 Area Total Runtime 53.173.3 84.7 Area Percent Difference 38.1% 59.6% from Standard *See Tables2, 3, and 4 above for formulations corresponding to numeric designations

TABLE 6 DIDP Containing Samples* 265-57-1 265-57-2 265-54-2 3000 μL 3000μL 200 μL 1st 30 Seconds 7.9 6.5 11.4 Area Total Runtime Area 59.4 56.487.3 Percent Difference −5.1% 46.9% from Standard *See Tables 2, 3, and4 above for formulations corresponding to numeric designations

TABLE 7 Polybutene and DIDP Containing Samples* 265-57-3 265-57-4265-54-2 3000 μL 3000 μL 200 μL 1st 30 Seconds Area 8.0 8.8 11.4 TotalRuntime Area 54.6 67.8 87.3 Percent Difference 24.3% 60.0% from Standard*See Tables 2, 3, and 4 above for formulations corresponding to numericdesignations

Testing Results:

Testing was completed in three different sets: products containing justpolybutene, products containing just DIDP, and products containing acombination of polybutene and DIDP. Each set was run twice, and the runswere averaged. There was a large disparity in the dosage of theproducts. The examples from Example II of the '925 patent, as well asthe analogs, needed a dosage of 3000 μL in order to produce anacceptable test, while experimental 265-54-2 needed only 200 μL, whileyielding results that ranged from 46.9 to 60.0% better performance.

Example 3 Testing the Effects of Surfactants

The '925 patent states that the addition of a water soluble surfactanthaving a cloud point of 21-38° C., at levels of 0.25% to 3%, increasesthe drainage properties of the examples while maintaining excellentdefoaming activity. In laboratory testing, the increase in drainage istypically measured as an increase in the performance of the defoamerduring the 30 seconds after the defoamer is introduced. In an effort totest the examples, experimental products were made using theformulations from Example II in the '925 patent, and adding 0.25% and 3%of an ethylene oxide/propylene oxide block copolymer surfactant whichmeets the water solubility and cloud point criteria. These experimentalproducts were tested and compared to the defoaming performance of265-54-2. As in the case of Example II above, analogs of each of thesamples were made using the Acrylate polymer in DIOA. Below are theformulations and test results obtained.

TABLE 8 Formulations Containing Polybutene and Ethylene Oxide/PropyleneOxide Block Copolymer Surfactant 265-56-1 265-56-2 265-56-3 265-56-4Polybutene 69.8 69.8 67 67 (MW = 370) Acrylate 30 30 Polymer in DIDPEthylene 0.3 0.3 3 3 Oxide/Propylene Oxide Block Copolymer Surfactant2EHA/2HEA 30 30 Polymer in DIOA

TABLE 9 Testing Results from Polybutene and Ethylene Oxide/PropyleneOxide Block Copolymer Surfactant Containing Defoamers* 265-56-1 265-56-2265-56-3 265-56-4 265-54-2 265-54-2 3000 μL 3000 μL 3000 μL 3000 μL 150μL 200 μL 1st 30 7.0 8.4 10.4 11.4 9.0 11.2 Seconds Area Total 55.3 72.669.1 79.3 68.7 84.7 Runtime Area Percent Difference 31.4% 25.0% 43.4%24.3% 53.3% from Standard *See Tables 4 and 8 above for formulationscorresponding to numeric designations

Testing Results:

From Table 9 above, testing results show 265-56-2, 265-56-4, and265-54-2 dosed at 200 μL, all of which contain the Acrylate polymer inDIOA outperform 265-56-1 and 256-56-3, both of which contain theAcrylate polymer in DIDP, regardless of the surfactant level. Testingalso shows that the 265-54-2 formulation dosed at 200 μL outperforms allof the other examples at 1/15^(th) the dosage, regardless of whichpolymer is present.

TABLE 10 Formulations Containing DIDP and Polybutene 265-58-1 265-58-2265-58-3 265-58-4 DIDP 69.8 69.8 67 67 Acrylate 30 30 Polymer in DIDPPolybutene 0.3 0.3 3 3 Acrylate 30 30 Polymer in DIOA

TABLE 11 Testing Results from DIDP and Polybutene Containing Defoamers*265-58-1 265-58-2 265-58-3 265-58-4 265-54-2 265-54-2 3000 μL 3000 μL3000 μL 3000 μL 150 μL 200 μL 1st 30 7.5 6.3 9.3 7.5 9.8 11.4 SecondsArea Total 58.3 55.9 65.0 62.8 69.4 87.3 Runtime Area Percent Difference−4.1% 11.5% 7.7% 19.0% 49.7% from Standard *See Tables 4 and 10 abovefor formulations corresponding to numeric designations

Testing Results:

The results in Table 11 above show that 265-58-3, which contains highlevels of DIDP diluent in conjunction with the Acrylate polymer in DIDPoutperforms 265-58-2 and 265-58-4, which contain the Acrylate polymer inDIOA diluted with DIDP. This difference in performance is within therange of experimental error. Testing also shows that the 265-54-2formulation outperforms all of the other examples at 1/15^(th) and1/20^(th) the dosage, regardless of which polymer is present.

TABLE 12 Formulations Containing DIDP, Polybutene and EthyleneOxide/Propylene Oxide Block Copolymer Surfactant 265-58-5 265-58-6265-58-7 265-58-8 Polybutene 50 50 50 50 DIDP 19.8 19.8 17 17 Acrylate30 30 Polymer in DIDP Ethylene 0.3 0.3 3 3 Oxide/Propylene Oxide BlockCopolymer Surfactant Acrylate 30 30 Polymer in DIOA

TABLE 13 Testing Results from DIDP, Polybutene and EthyleneOxide/Propylene Oxide Block Copolymer Surfactant Containing Defoamers*265-58-5 265-58-6 265-58-7 265-58-8 265-54-2 265-54-2 3000 μL 3000 μL3000 μL 3000 μL 150 μL 200 μL 1st 30 8.0 9.2 10.5 10.4 9.8 11.4 SecondsArea Total 56.1 68.5 63.4 64.8 69.4 87.3 Runtime Area Percent Difference22.1% 13.1% 15.6% 23.6% 55.6% from Standard *See Tables 4 and 12 abovefor formulations corresponding to numeric designations

Testing Results:

These test results show that 265-58-6 and 265-58-8, which contain theAcrylate polymer in DIOA consistently outperforms 265-58-7, regardlessof the surfactant level. Testing also shows that the 265-54-2formulation outperforms all of the examples at 1/15^(th) and 1/20^(th)the dosage, regardless of which polymer is present.

Example 4 Efficacy of the Defoamer Formulations

To test the efficacy of the defoamer formulations, products were madeand tested against 265-54-2. Below are the formulations and test resultsfrom this testing.

TABLE 14 Formulations Containing Hydrophobic Silica 265-59-1 265-59-2Acrylate 30 Polymer in DIDP Acrylate 30 Polymer in DIOA Hydrophobic 5 5Silica DIDP 15 15 Polybutene 50 50

TABLE 15 Testing Results from Defoamer Formulations ContainingHydrophobic Silica* 265-59-1 265-59-2 265-54-2 3000 μL 3000 μL 200 μL1st 30 Seconds Area 12.3 12.3 11.0 Total Runtime Area 72.3 74.4 85.4Percent Difference 2.9% 18.1% from Standard *See Tables 4 and 14 abovefor formulations corresponding to numeric designations

Testing Results:

Testing did show an increase in performance of 265-59-2 when 5%hydrophobic silica was incorporated into the products. However, 265-59-2did not perform as well as 265-54-2, even at 15 times the dosage.Repeated testing of experimental defoamer 265-54-2 shows superiordefoaming capabilities. A dosage of 3000 μL, (approximately 60 ppm) isconsidered excessive in laboratory testing of first stage black liquorfiltrate. A typical dosage for an oil based defoamer in 1^(st) stageblack liquor is typically 250-500 μL.

It was first assumed the change from DIDP to DIOA was neutral, based onFoam Cell test (measuring foam height vs. time) results, but uponbeginning testing and evaluation of developed samples using the FEATunit to evaluate samples (FEAT measures liquid density over time) it wasdiscovered there was in fact a difference between the two polymersystems; the polymer made in DIOA performed better than the polymer madein DIDP.

Example 5 Direct Comparison of the Polymer in the Different Diluents

Samples were made and tested in an effort to test whether the diluentused affects the performance of the polymer in the FEAT unit. Below arethe formulations of the products and the results from the testing.

TABLE 16 Formulations of Polymers made and Diluted in Different Diluents265-57-1 265-57-2 265-83-1 265-83-2 Acrylate Polymer 30 30 in DIDPAcrylate Polymer 30 30 in DIOA DIDP 70 70 DIOA 70 70

TABLE 17 Results from Testing Polymers in DIDP 265-57-1 265-57-2 3000 μL3000 μL 1st 30 Seconds Area 7.9 6.5 Total Runtime Area 59.4 56.4 PercentDifference from −5.1% Standard

TABLE 18 Results from Testing Polymers in DIOA 265-83-1 265-83-2 3000 μL3000 μL 1st 30 Seconds Area 1.7 1.2 Total Runtime Area 6.8 8.3 PercentDifference from 21.8% Standard

Testing Results:

Table 17 shows that the Acrylate polymer in DIOA, when diluted in DIDP,has slightly lower performance than the Acrylate polymer in DIDP dilutedin DIDP, but within experimental error. Table 18 shows that the Acrylatepolymer in DIOA, when diluted in DIOA, improves the performance 22% over2EHA/2HEA polymer in DIDP diluted with DIOA.

Example 6 Improvement of Acrylate Polymer in DIOA with Acrylic Acid

Experiments were conducted in an effort to determine if the performanceof the Acrylate polymer in DIOA could be improved. The procedures ofExample 1 above were repeated to prepare and evaluate a series ofpolymers to determine their defoaming capacity. These products wereproduced by lowering the amount of hydroxyalkyl acrylate and alkylacrylate in the DIOA diluted polymer and replacing that amount withglacial acrylic acid, which was added into the premix of the monomers.The resulting polymers where used as a replacement for the polymercomponent of 265-54-2. Below is the mol % of acrylic acid added to themonomer pre-mix, as well as the formulations and results from thetesting.

TABLE 19 Mol % Acrylic Acid in Polymer Numeric Mol % Acrylic DesignationAcid in Polymer 265-64 1% 265-60 4.3%   265-65 8% 265-67 20% 

TABLE 20 Formulations with Acrylic Acid Polymers 265-66-1 265-61265-66-2 265-68 Polypropylene Glycol 31.5 31.5 31.5 31.5 10% HydrophobicSilica 30 30 30 30 Base in Polypropylene Glycol Polyether-Modified 10 1010 10 Polysiloxane Silicone Surfactant Alkyl Modified Siloxane 5 5 5 5Silicone Wax 265-64 23.5 265-60 23.5 265-65 23.5 265-67 23.5

TABLE 21 Performance of Formulations Containing Acrylic Acid Polymers*265-54-2 Acrylate Polymer 265-66-1 265-61 265-66-2 265-68 in DIOA 1 Mol% 4 Mol % 8 Mol % 20 Mol % 1st 30 9.3 9.6 9.6 10.2 10.7 Seconds AreaTotal 40.1 50.2 52.5 56.6 54.4 Runtime Area Percent Difference 25.4%31.0% 41.4% 35.9% from Standard *See Tables 4 and 20 above forformulations corresponding to numeric designations

Testing Results:

The testing shows that by including acrylic acid in the monomer premix,the resulting polymer provides a significant increase in performance tothe final defoamer formulation when compared to 265-54-2, which has noacrylic acid. This improved performance was well beyond the increasethat was observed by switching from DIDP to DIOA. Thus, this level ofincrease was unexpected.

Effect of Different Diluents on Performance:

After showing that the addition of 8 mol % acrylic acid to the Acrylatepolymer in DIOA significantly improves performance, samples of thepolymer were made in DIDP to examine if the difference in diluent willaffect performance. The manufacturing procedure from Example 1 above wasused, whereby the DIOA was replaced with DIDP. The resulting polymer,265-84, was a very viscous liquid (>140,000 cps). The products that weremade using 265-84 were tested against the products made from DIOA analog265-65. Below are the formulations and results from the testing.

TABLE 22 Formulations Containing 8 Mol % Acrylic Acid 265-85-1 265-85-2265-85-3 265-85-4 DIDP 70 70 DIOA 70 70 265-65 30 30 8 Mol % in DIOA265-84 30 30 8 Mol % in DIDP

TABLE 23 Results of Testing the 8 Mol % Polymers 265-85-1 265-85-2265-85-3 265-85-4 Avg Avg Avg Avg 2500 μL 2500 μL 2500 μL 2500 μL 1st 303.1 7.3 5.4 8.0 Seconds Area Total 3.2 37.9 34.3 63.7 Runtime AreaPercent Difference 1093.2% 979.3% 1904.6% from Standard

Testing Results:

Table 23 shows that 8 mol % polymer, 265-85-4, made in DIOA and dilutedwith DIOA outperforms polymer, 265-85-3, made in DIOA and diluted withDIDP. Polymer, 265-85-2, made in DIDP and diluted with DIOA evenoutperforms 265-85-3. Also, an increase in performance of over 1900% wasobserved over the standard. Although an increase in performance wasexpected, an increase of over 1900% certainly was not.

Effect of 8 Mol % Acrylic Acid:

The 8 mol % acrylic acid polymer was tested against Acrylate polymer inDIDP and Acrylate polymer in DIOA. Below are the formulations andresults from the testing.

TABLE 24 Formulations Containing 8 Mol % Acrylic Acid Acrylate AcrylatePolymer in Polymer in DIDP DIOA 8 Mol % 2EHA/2HEA 30 Polymer in DIDPDIDP 70 2EHA/2HEA 30 Polymer in DIOA DIOA 70 70 265-65 8 Mol % 30Acrylic Acid

TABLE 25 Results from 8 Mol % Acrylic Acid Testing in DIOA 8 Mol %Acrylate Acrylate Acrylic Polymer in Polymer in Acid in DIDP Avg DIOAAvg DIOA Avg 1st 30 4.9 6.6 8.9 Seconds Area Total 39.4 47.9 60.8Runtime Area Percent Difference from 21.4% 54.4% Standard

Testing Results:

Testing shows that the product containing 8 mol % acrylic acid performed54% better than the product containing Acrylate polymer in DIDP, and 33%better than the product containing Acrylate polymer in DIOA.

Example 7 Comparison to Oil Based Defoamers

One of the criteria that was set for the present invention was that thenewly created defoamer formulations must perform as well as traditionaloil based defoamers (paraffinic oil, EBS, silicone fluid, hydrophobicsilica). The oil based defoamer that was chosen as the standardcontained 4.9% EBS, 4.5% hydrophobic silica, 0.5% Polydimethylsiloxane(PDMS) silicone fluid, 0.5% silicone surfactant, and the remainder asparaffinic oil. This defoamer was tested against different experimentaldefoamers at equal dosages (150 μL) in 82° C. first stage filtrate.Below are the formulations and results from the testing.

TABLE 26 Results for New Formulations Versus Traditional Oil BasedDefoamer* 265-54-2 Acrylate Oil Base Polymer 265-66-1 265-61 265-66-2265-68 Defoamer in DIOA 1 Mol % 4 Mol % 8 Mol % 20 Mol % 1st 30 8.7 6.26.6 6.5 7.1 7.6 Seconds Area Total 10.7 23.5 33.7 35.9 40.1 37.9 RuntimeArea Percent Difference 120.2% 215.4% 236.5% 275.5% 254.9% from Standard*See Tables 4 and 20 above for formulations corresponding to numericdesignations

Testing Results:

Testing shows that defoamer, 265-54-2, containing the DIOA dilutedpolymer from Example 1 above provided a 120% increase in performanceover the oil base standard. With an 8 mol % addition of acrylic acid topolymer, 265-66-2, there is an unexpected increase of 275.5% inperformance over traditional oil based defoamers.

Acrylic Acid Polymer at Different Concentrations:

The 8 mol % acrylic acid polymer was tested against Acrylate polymer inDIDP and Acrylate polymer in DIOA in an oil based defoamer formulationat 3, 6, and 10%. Below are the formulations and results from thetesting.

TABLE 27 Oil Based Formulations Generic Oil Base: EBS 2% Hydrophobic 2%Silica Paraffinic Oil 96% Products Tested: 265- 265- 265- 265- 265- 265-265- 265-94-2 94-3 94-4 94-5 94-6 94-7 94-8 94-9 265-94-10 Generic Oil97% 97% 97% 94% 94% 94% 90% 90% 90% Base Acrylate 3% 6% 10% Polymer inDIDP Acrylate 3% 6% 10% Polymer in DIOA 8 Mol % 3% 6% 10% Acrylic Acid

TABLE 28 Results from Oil Based Defoamer Testing with 3% Polymer 3%Polymer 265-94-2 265-94-3 265-94-4 1st 30 Seconds 12.0 12.1 10.7 AreaTotal Runtime 49.5 50.8 44.6 Area Percent Difference from 2.6% −10.0%Standard

Testing Results:

Testing shows that the acrylic acid containing polymer, 265-94-4, doesnot perform as well as the Acrylate polymer in DIDP or the Acrylatepolymer in DIOA at 3% concentration.

TABLE 29 Results from Oil Based Defoamer Testing with 6% Polymer 6%Polymer 265-94-5 265-94-6 265-94-7 1st 30 Seconds 10.6 11.1 10.5 AreaTotal Runtime 43.8 44.1 46.1 Area Percent Difference from 0.7% 5.2%Standard

Testing Results:

Testing shows that the use of acrylic acid containing polymer, 265-94-7,increases performance when added at 6%, but the increase is withinexperimental error.

TABLE 30 Results from Oil Based Defoamer Testing with 10% Polymer 10%Polymer 265-94-8 265-94-9 265-94-10 1st 30 10.8 10.8 10.4 Seconds AreaTotal 40.9 40.1 53.5 Runtime Area Percent Difference −1.9% 31.0% fromStandard

Testing Results:

Testing shows that a 10% addition of acrylic acid containing polymer,265-94-10, in an oil based defoamer increases performance 31% over theAcrylate polymer in DIDP, and 29% over the Acrylate polymer in DIOA.

Dosage Needed to Match the Performance of the Defoamers of the PresentInvention

Tests were completed to determine the dosage of the oil based defoamerthat was needed in order to match the performance of the polymericcontaining defoamers of the present invention. Below are the resultsfrom that testing.

TABLE 31 Results Showing the Amount of Oil Based Defoamer Needed toMatch Polymeric Performance 265-54-2 Oil Base Acrylate 265-66-2 Oil BaseDefoamer Polymer in 8 Mol % Defoamer 200 μL DIOA 200 μL 200 μL 1000 μL1st 30 Seconds Area 12.1 10.5 10.7 14.1 Total Runtime Area 21.8 76.282.4 83.9 Percent Difference from 249.9% 278.3% 285.1% Standard

Testing Results:

Results show that 1000 μL, of oil based defoamer was needed to match theperformance of polymeric defoamer, 265-66-2, containing theacrylate/acrylic acid polymer. This represents a five-fold increase indefoamer dosage over the experimental polymeric defoamers.

Example 8 Silicone Emulsion Defoamer Testing

The different polymers were tested in a silicone emulsion in an attemptto measure the affect of the polymer on performance. Below are theformulations and results from the testing.

TABLE 32 Silicone Emulsion Formulations* 265- 265- 265- 95-1 95-2 95-3265-96-1 265-96-2 265-96-3 Silicone 99 99 99 98 98 98 Emulsion Acrylate1 2 Polymer in DIDP Acrylate 1 2 Polymer in DIOA 8 Mol % 1 2 AcrylicAcid *Polymers were added into the formulation during productmanufacture, not as a post-add.

TABLE 33 Results from Silicone Emulsion Testing 265-95-1 265-95-2265-96-1 265-96-2 1% 1% 2% 2% Acrylate Acrylate 265-95-3 AcrylateAcrylate 265-96-3 Polymer Polymer 1% Polymer Polymer 2% in DIDP in DIOA8 Mol % in DIDP in DIOA 8 Mol % Avg Avg Avg Avg Avg Avg 1st 30 8.6 9.18.1 8.8 7.2 8.3 Seconds Area Total 36.6 41.2 27.6 37.8 22.2 20.3 RuntimeArea Percent Difference 12.4% −24.7% 3.1% −39.5% −44.6% from Standard

Testing Results:

Testing shows that increasing the amount of polymer in the siliconeemulsion formulation decreases performance with polymer, 265-96-3,containing 8 mol % acrylic acid having the poorest performance.

Silicone Concentrate Testing:

The different polymers were examined in a silicone concentrate defoamerat 3, 6, and 10%. Below are the formulations and results from thetesting.

TABLE 34 Silicone Concentrate Defoamer Formulations 265- 265- 265- 265-265- 265- 265-97-2 265-97-3 265-97-4 97-5 97-6 97-7 97-8 97-9 97-10Generic 97 97 97 94 94 94 90 90 90 Silicone Defoamer Base: Acrylate 3 610 Polymer in DIDP Acrylate 3 6 10 Polymer in DIOA 8 Mol % 3 6 10Acrylic Acid *Polymer was post-added to the silicone defoamer and mixedfor 10 minutes.

TABLE 35 Results from Silicone Concentrate Testing Table 35A 265-97-2265-97-3 265-97-5 3% 3% 6% Acrylate Acrylate 265-97-4 Acrylate Polymerin Polymer in 3% Polymer in DIDP DIOA 8 Mol % DIDP 1st 30 9.3 8.9 8.79.9 Seconds Area Total 27.4 25.5 17.3 29.6 Runtime Area PercentDifference from −0.1 −0.4 0.1 Standard Table 35B 265-97-6 265-97-8265-97-9 6% 10% 10% Acrylate 265-97-7 Acrylate Acrylate 265-97-10Polymer 6% Polymer Polymer 10% in DIOA 8 Mol % in DIDP in DIOA 8 Mol %1st 30 9.5 10.2 8.5 8.5 9.9 Seconds Area Total 24.6 18.3 21.0 17.2 15.1Runtime Area Percent −0.1 −0.3 −0.2 −0.4 −0.4 Difference from Standard

Testing Results:

Testing shows that varying the polymers in different silicone defoamerconcentrations have no effect on performance.

Example 9 Methacrylic Acid Addition

Reactions were completed where the acrylic acid was replaced withmethacrylic acid. The procedure for manufacturing the polymer was thesame as with the acrylic acid (see Example 6 above). The methacrylicacid was added to the Acrylate polymer at 8 mol %. The resulting polymerhas the numerical designation 296-4. The polymer was clear, with aviscosity of 27,750 cps as measured by a Brookfield RVT viscometer,spindle 6, speed 60. The methacrylic acid polymer was then tested in thepolymeric defoamer formulation as a direct substitution. Below are theformulations tested and the results from the testing.

TABLE 36 Polymeric Formulations Containing 23.5% Polymer 265-100-4265-100-5 265-100-6 296-6 Polypropylene 31.5 31.5 31.5 31.5 Glycol 10%30 30 30 30 Hydrophobic Silica in Polypropylene Glycol Polyether- 10 1010 10 Modified Polysiloxane Silicone Surfactant Alkyl Modified 5 5 5 5Siloxane Silicone Wax Acrylate Polymer 23.5 in DIDP Acrylate Polymer23.5 in DIOA 8 Mol % Acrylic 23.5 Acid 8 Mol % 23.5 Methacrylic Acid

TABLE 37 Results from Polymeric Defoamer Testing 265-100-4 265-100-5Acrylate Acrylate 265-100-6 296-6 Polymer Polymer in 8 Mol % 8 Mol % inDIDP DIOA Acrylic Methacrylic Avg Avg Avg Avg 1st 30 4.2 4.3 5.3 6.0Seconds Area Total 25.5 28.8 32.5 34.4 Runtime Area Percent Difference12.9% 27.6% 34.9% from Standard

Testing Results:

Testing of the polymeric defoamers containing 23.5% polymer shows theaddition of polymer 296-6, containing 8 mol % methacrylic acid,increases performance when compared to the use of the Acrylate polymerin DIDP, the Acrylate polymer in DIOA, or the polymer containing 8 mol %acrylic acid.

Example 10 Preparation of Methacrylate Polymers

After showing that substitution of methacrylic acid for acrylic acid inthe acrylate polymer leads to an increase in defoamer performance,experiments were completed that replaces all of the acrylate monomerswith the methacrylate analogs, as well as the acrylic acid withmethacrylic acid. The methods and procedures of Example 1 were used toproduce the polymers.

In the first experiment, 250 g of DIOA was placed into a reaction flask.A vacuum was applied for 20 minutes to remove dissolved air. The DIOAwas sparged with nitrogen while being heated to 79-82° C. with mixing.Once at temperature and with the nitrogen sparge and constant mixing,1.5 g of a free radical generating compound was added and allowed todissolve over a 5 minute period. Meanwhile, 33.22 g of 2-hydroxyethylmethacrylate, 153.22 g of 2-ethylhexyl methacrylate, and 13.56 g ofmethacrylic acid were pre-mixed in a beaker. The mixture was added tothe DIOA diluent through an addition funnel at a rate of approximately1.0 g/minute, making sure to maintain a temperature of approximately79-82° C. After 25 minutes, the mixture began to cloud. After 1.5 hours,the mixture in the reaction flask was viscous enough to overload themixer. The mixer was replaced, but the mixture was too thick to stir.The heat was turned off. 42.2 g of the monomer mixture was present inthe addition tube, leading to 157.8 g of monomer mixture in the reactionflask. The resulting polymer was allowed to cool. The polymer was solidat room temperature.

A second experiment was completed with a more dilute monomerconcentration to allow for the reaction to run to completion while stillbeing able to mix the resultant polymer. Again, the methods andprocedures of Example 1 were used to produce the polymers.

250 g of DIOA was placed into a reaction flask. A vacuum was applied for20 minutes to remove dissolved air. The DIOA was sparged with nitrogenwhile being heated to 79-82° C. with mixing. Once at temperature andwith the nitrogen sparge and constant mixing, 1.5 g of a free radicalgenerating compound was added and allowed to dissolve over a 5 minuteperiod. Meanwhile, 8.79 g of 2-hydroxyethyl methacrylate, 40.56 g of2-ethylhexyl methacrylate, and 3.59 g of methacrylic acid were pre-mixedin a beaker. The mixture was added to the DIOA diluent through anaddition funnel at a rate of approximately 1.0 g/minute, making sure tomaintain a temperature of approximately 79-82° C. After the monomermixture was added, the addition funnel and tube was rinsed with 48 g ofDIOA, and then 0.5 g of free radical generating compound was added.Another 0.5 g of free radical generating compound was added, and themixture was held at 79-82° C. with mixing and nitrogen for 2 hours. Themixture was then air cooled to room temperature. The resulting polymerwas a cloudy liquid with a viscosity of 400 cps. The numeric designationfor this product is 296-14.

Performance testing of polymer, 296-14, was completed againstformulations 296-15-1,2,4, and 5, shown below in Table 38. The polymerswere formulated into polymeric defoamers, and the defoamers were testedin 100% black liquor at 82° C. Below are the formulations and resultsfrom the testing.

TABLE 38 Polymeric Defoamer Formulations 296- 296- 15-1 296-15-2296-15-3 296-15-4 15-5 Polypropylene 25 25 25 25 25 Glycol 10% 30 30 3030 30 Hydrophobic Silica in Polypropylene Glycol Acrylate 11.3 Polymerin DIDP Acrylate 11.3 Polymer in DIOA 296-14 30 8 Mol % Acrylic 11.3 8Mol % 11.3 Methacrylic Polyether- 10 10 10 10 10 Modified PolysiloxaneSilicone Surfactant Alkyl Modified 5 5 5 5 5 Siloxane Silicone Wax DIOA18.8 18.8 18.8 18.8

TABLE 39 Results from Testing the Methacrylate/Methacrylic Acid Polymer.296-15-3 296-15-1 296-15-2 Methacrylate/ Acrylate Acrylate MethacrylicPolymer Polymer Acid in DIDP in DIOA Polymer 1st 30 Seconds Area 5.9 5.76.9 Total Runtime Area 31.7 31.2 46.9 Percent Difference from −1.5%48.1% Standard

Testing Results:

Testing shows that a polymer comprising hydroxyalkyl methacrylate, alkylmethacrylate, and methacrylic acid, when formulated into defoamer296-15-3, provides increased initial air removal and increased longevitywhen compared to polymers 296-15-1 and 2, consisting of hydroxyalkylacrylate and alkyl acrylate. A defoamer formulation containing the abovepolymer, 296-14, outperforms defoamer formulations 296-15-1 and 2 by asmuch as 48%.

SUMMARY AND CONCLUSIONS

The potential benefits of a defoamer that contains an alkylacrylate/hydroxyalkyl acrylate/acrylic acid polymer are clearlydemonstrated herein. Notable improvements in initial performance andlongevity were realized by incorporating the polymer into a formulationcontaining polypropylene glycol, hydrophobic silica, and siliconesurfactants. This approach is new in terms of defoamers used inindustrial settings.

The use of monomers other than alkyl acrylate/hydroxyalkylacrylate/acrylic acid that may be used to produce a polymer thatprovides increased defoaming performance has been demonstrated herein.The alternate monomers may include methacrylic acid, 2-ethylhexylmethacrylate, 2-hydroxyethyl methacrylate, and the butyl analogs of theacrylates and methacrylates.

The final formulations for use will be determined based on the operatingparameters of a given application, i.e. the alkalinity, temperature, andthe need for dispersibility. The final product(s) will be tailored forindividual needs.

All patents, patent applications and publications cited in thisapplication are hereby incorporated by reference in their entirety forall purposes to the same extent as if each individual patent, patentapplication or publication were so individually denoted.

Although certain embodiments and examples have been described in detailabove, those having ordinary skill in the art will clearly understandthat many modifications are possible in the embodiments and exampleswithout departing from the teachings thereof. All such modifications areintended to be encompassed within the below claims of the invention.

1. A defoamer formulation comprising 0.01 to 50% by weight of an acrylate polymer with 1-20 mol % acrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation.
 2. The defoamer formulation of claim 1, wherein the acrylate polymer comprises acrylate monomers of the following general formula:

R is hydrogen or a linear or a branched alkyl group comprising from about 1 to 18 carbon atoms and optionally at least one hydroxy group.
 3. The defoamer formulation of claim 2, wherein the acrylate polymer is a product of a polymerization reaction between 2-ethylhexyl acrylate monomer, 2-hydroxyethyl acrylate monomer, and acrylic acid monomer.
 4. The defoamer formulation of claim 1, comprising 20-30% by weight hydroxyalkyl/alkyl acrylate polymer with 8 mol % acrylic acid monomer, based on a total weight of the formulation.
 5. The defoamer formulation of claim 1, wherein the suitable diluent is selected from diisodecyl phthalate, diisooctyl adipate, bis-2-ethylhexyl adipate, dioctyl adipate, 2-ethyl-1-hexanol, isooctyl alcohol, dihexyl phthalate, or mixtures thereof.
 6. The defoamer formulation of claim 5, wherein the suitable diluent is diisoctyl adipate.
 7. The defoamer formulation of claim 1, comprising 40-60% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation.
 8. The defoamer formulation of claim 1, comprising 3-10% by weight of an additive, based on a total weight of the formulation.
 9. The defoamer formulation of claim 1, wherein the additive is selected from hydrophobic silica, waxes, fatty alcohols, fatty acids, or mixtures thereof.
 10. The defoamer formulation of claim 9, wherein the additive is hydrophobic silica.
 11. The defoamer formulation of claim 1, comprising 10-15% by weight surfactants, based on a total weight of the formulation.
 12. The defoamer formulation of claim 1, wherein the surfactant is selected from polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol,alkoxylated dimethylpolysiloxane, alkyl modified siloxanes, fluorine modified siloxanes, mercapto modified siloxanes, hydroxy modified siloxanes, siloxane wax, ethylene oxide/propylene oxide block copolymer, the esters of polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol, ethylene oxide/propylene oxide block copolymer, alkylpolyoxyethylene ethers, alkylpolyoxyethylenes, polyoxypropylene ethers, fatty acid polyoxyethylene esters, fatty acid polyoxyethylene sorbitan esters, fatty acid polyoxypropylene sorbitol esters, polyoxyethylene castor oils, alkylpolyoxyethylene amines and amides, fatty acid sorbitan esters, fatty acid polyglycerin esters, fatty acid sucrose esters, or mixtures thereof.
 13. The defoamer formulation of claim 12, wherein the surfactant is a siloxane wax.
 14. The defoamer formulation of claim 1, comprising 23.5% by weight acrylate polymer with 8 mol % acrylic acid in diisooctyl adipate, based on a total weight of the formulation, 51.5% by weight polypropylene glycol, based on a total weight of the formulation, 10% by weight hydrophobic silica, based on a total weight of the formulation, and 15% by weight siloxane wax, based on a total weight of the formulation.
 15. A defoamer formulation comprising 0.01 to 50% by weight of a methacrylate polymer with 1-20 mol % methacrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation.
 16. The defoamer formulation of claim 15, wherein the methacrylate polymer comprises methacrylate monomers of the following general formula:

R is hydrogen or a linear or a branched alkyl group comprising from about 1 to 18 carbon atoms and optionally at least one hydroxy group.
 17. The defoamer formulation of claim 16, wherein the methacrylate polymer is a product of a polymerization reaction between 2-ethylhexyl methacrylate monomer, 2-hydroxyethyl methacrylate monomer, and methacrylic acid monomer.
 18. The defoamer formulation of claim 15, comprising 20-30% by weight hydroxyalkyl/alkyl methacrylate polymer with 8 mol % methacrylic acid monomer, based on a total weight of the formulation.
 19. The defoamer formulation of claim 15, wherein the suitable diluent is selected from diisodecyl phthalate, diisooctyl adipate, bis-2-ethylhexyl adipate, dioctyl adipate, 2-ethyl-1-hexanol, isooctyl alcohol, dihexyl phthalate, or mixtures thereof.
 20. The defoamer formulation of claim 19, wherein the suitable diluent is diisooctyl adipate.
 21. The defoamer formulation of claim 15, comprising 40-60% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation.
 22. The defoamer formulation of claim 15, comprising 3-10% by weight of an additive, based on a total weight of the formulation.
 23. The defoamer formulation of claim 15, wherein the additive is selected from hydrophobic silica, waxes, fatty alcohols, fatty acids, or mixtures thereof.
 24. The defoamer formulation of claim 23, wherein the additive is hydrophobic silica.
 25. The defoamer formulation of claim 15, comprising 10-15% by weight surfactants, based on a total weight of the formulation.
 26. The defoamer formulation of claim 15, wherein the surfactant is selected from polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol,alkoxylated dimethylpolysiloxane, alkyl modified siloxanes, fluorine modified siloxanes, mercapto modified siloxanes, hydroxy modified siloxanes, siloxane wax, ethylene oxide/propylene oxide block copolymer, the esters of polyethylene glycol, polypropylene glycol, polypropylene triol, butoxy polypropylene polyethylene glycol, ethylene oxide/propylene oxide block copolymer, alkylpolyoxyethylene ethers, alkylpolyoxyethylenes, polyoxypropylene ethers, fatty acid polyoxyethylene esters, fatty acid polyoxyethylene sorbitan esters, fatty acid polyoxypropylene sorbitol esters, polyoxyethylene castor oils, alkylpolyoxyethylene amines and amides, fatty acid sorbitan esters, fatty acid polyglycerin esters, fatty acid sucrose esters, or mixtures thereof.
 27. The defoamer formulation of claim 26, wherein the surfactant is a siloxane wax.
 28. The defoamer formulation of claim 15, comprising 30% by weight methacrylate polymer with 8 mol % methacrylic acid, based on a total weight of the formulation, 45% by weight polypropylene glycol, based on a total weight of the formulation, 10% by weight hydrophobic silica, based on a total weight of the formulation, and 15% by weight siloxane wax, based on a total weight of the formulation.
 29. A method of reducing or preventing the generation of foam, comprising adding the defoamer formulation of claim 1 before, during, or after said foam is generated.
 30. A method of reducing or preventing the generation of foam, comprising adding the defoamer formulation of claim 15 before, during, or after said foam is generated.
 31. A method for preparing the defoamer formulation of claim 1 comprising mixing 0.01 to 50% by weight of an acrylate polymer with 1-20 mol % acrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation.
 32. A method for preparing the defoamer formulation of claim 15 comprising mixing 0.01 to 50% by weight of a methacrylate polymer with 1-20 mol % methacrylic acid in a suitable diluent, based on a total weight of the formulation, 20-80% by weight of an organic carrier that consists of polypropylene glycol, based on a total weight of the formulation, 0.01 to 15% by weight of an additive, based on a total weight of the formulation, and optionally, 0.01 to 30% by weight of a surfactant, based on a total weight of the formulation. 